A Cu

Area of Science:

• Organic Chemistry
• Materials Science
• Photochemistry

Background:

• Rhodamine B hydrazide hydrazone (RhBHH) derivatives are known for their photochromic properties.
• Understanding the structure-property relationship is crucial for designing novel photochromic materials.
• Previous studies suggested limited influence of certain substituents on RhBHH photochromism.

Purpose of the Study:

• To investigate the structure-photochromic response relationship (SPRR) of novel RhBHH derivatives.
• To explore the effect of various substituent groups, particularly halogens, on Cu2+-triggered photochromism.
• To evaluate the potential applications of these new photochromic systems.

Main Methods:

• Synthesis of fifteen RhBHH derivatives (compounds a-o) with diverse substituent groups.
• Systematic study of their photochromic properties triggered by Cu2+ ions.
• Detailed characterization of photochromic behavior using compound g as a model.

Main Results:

• Three derivatives (f-h) with para-hydroxyl and meta-halogen substituents exhibited significant Cu2+-triggered photochromism, differing from prior reports.
• Halogen atoms were found to exert a considerable influence on the photochromic behavior of RhBHH derivatives.
• Compound g demonstrated high selectivity for Cu2+ as a trigger, with good reversibility upon visible light irradiation and dark/heat bleaching.

Conclusions:

• Halogen substituents play a critical role in tuning the photochromic response of RhBHH derivatives.
• The developed photochromic system shows potential for applications in photochromic glass, security inks, and data storage.
• This study provides valuable insights into the SPRR for designing advanced photochromic materials.